无机化学实验问题例析

Discussion about the Question of Inorganic Chemistry Experiment

就学生在无机化学实验教学过程中提出的问题作一解答。认为:(1)Cr3+与NH3.H2O作用主要是生成Cr(OH)3,而不是[Cr(NH3)6]3+离子;(2)在有NH4+时,Zn(OH)2易溶于NH3.H2O;(3)[Co(NO2)6]3-溶液中加入强酸,其分解产物是Co2+,不是Co3+;(4)[Fe(SCN)6]3-遇H2O2,血红色消失的原因是过量的H2O2氧化了SCN-。

The paper attempts to solve the problem posed by students in the process inorganic chemistry experimenting teaching. This paper points out Cr^3＋ and NH3·H2O functions mainly give birth to chrome hydroxide, not the chrome （ III ） ammonia matches with the thing; when the NH4^＋ exists, the zinc hydroxide is easily dissolved in the ammonia water; if it is put in the aqua of [ Co （ NO2） 6 ]^3 - strong acid, its resolution outcome is cobalt （ II ）, not cobalt （ III ） ; the Fe （SCN） N^3- meet H2O2, the reason why blood-red color disappears is the H2O2 of surfeit to oxidize the SCN^-.